1. Field of the Invention
The present invention relates to an ink jet printer, and, more particularly, to an ink jet printer that prints using chromatic inks of multiple types, such as a chromatic dye-based ink and a chromatic pigment-based ink.
2. Description of the Related Art
An ink jet printer forms an image on a print media sheet by ejecting ink from a plurality of ink jetting nozzles of an ink jet printhead to form a pattern of ink dots on the print media sheet. Such an ink jet printer may include a reciprocating printhead carrier that transports multiple ink jet printheads across the print media sheet along a bi-directional scanning path defining a print zone of the printer. Typically, a mid-frame provides media support at or near the print zone. A sheet feeding mechanism is used to incrementally advance the print media sheet in a sheet feed direction, also commonly referred to as a sub-scan direction or vertical direction, through the print zone between scans in the main scan direction, or after all data intended to be printed with the print media sheet at a particular stationary position has been completed.
It is known to provide a unitary printhead cartridge that includes both a printhead and a local supply of ink. Further, it is known to provide a multi-chambered printhead cartridge for carrying multiple colors of ink, or alternatively, to provide individual printhead cartridges, each including a separate supply of ink of a particular color. In one printing system, for example, it is known to mount a multi-chambered printhead cartridge including dye-based cyan (C), magenta (M) and yellow (Y) inks in one receptacle in the printhead carrier and to mount a pigment-based black (K) cartridge in another receptacle in the printhead carrier. These CMY color inks are typically of a single high concentration. However, due to the granularity of images formed with these high concentration inks, it was difficult to create near photographic quality images.
To overcome this granularity problem, diluted inks have been employed. The diluted inks are used to reproduce the less intense colors of the CIELAB system while the more intense colors require the use of the high concentration inks. Typically, only diluted forms of the cyan and magenta are used for a total of six different inks, i.e., cyan, magenta, yellow, black, diluted cyan and diluted magenta (CMYKcm).
The CIELAB system mentioned above is a color space to be used for the specification of color differences. The CIELAB system consists of three variables (L*, a*, and b*) as Cartesian coordinates to form a three-dimensional color space. The L* variable indicates perceived color lightness ranging from 0.0 for black to 100.0 for a diffuse white. The a* and b* dimensions respectively correspond to the red-green and yellow-blue hue/chroma perceptions. Accordingly, color can be defined within the CIELAB system based on lightness, hue (H*ab) and chroma (C*ab), wherein hue is a color in the a* and b* plane represented by a vector angle (hue angle) and chroma is the level of color saturation, ranging from 0.0 (corresponding to an intersection with the lightness (L*) axis) to total saturation, represented by the extent of the vector from the lightness (L*) axis.
As used herein, an achromatic ink is defined as an ink having a chroma of approximately 0 to 10 percent of full saturation on the chroma scale, i.e., substantially lying on the L* axis, ranging from black to white with various shades of gray therebetween, and a chromatic ink is defined as an ink having a chroma greater than 10 percent of full saturation. As an example, a dilute ink and a high concentration ink may have substantially the same hue, e.g., cyan, but will have different chroma, wherein the dilute ink has a relatively lower chroma than the high concentration ink. For example, a high concentration ink may have a chroma of between 80 and 100 percent of full saturation on the chroma scale, whereas the low concentration ink may have a chroma of 20 to 70 percent of full saturation on the chroma scale.
In another known system, printhead cartridges are arranged in the sequence K, A, B, C, M, and Y, with K being a dye-based black ink dispenser, A and B being pigment-based black ink dispensers, C being a dye-based cyan ink dispenser, M being a dye-based magenta ink dispenser, and Y being a dye-based yellow ink dispenser.
What is needed in the art, however, is an ink jet printer that prints using chromatic inks of multiple types, such as a chromatic dye-based ink and a chromatic pigment-based ink.